Profiled key for cylinder locks

ABSTRACT

A key for use in a cylinder lock with a rotatable key plug having an elongated key blade with a relatively wide lower portion and a relatively narrow upper portion. A step-like transition region between the wider lower portion and the narrow upper portion. The key blade includes a longitudinal profile groove located adjacent to the step-like transition region that extends along at least a portion of the length of the blade. An inner wall of groove is substantially parallel to a side surface of the lower portion of the key blade. The longitudinal profile groove includes an undercut portion adjacent to and inside a ridge portion of the key blade. The outside of ridge portion forms apart of the side surface of the blade in the relatively wide lower portion up to the step-like transition region and the inside of ridge portion facing inner wall of the groove.

This application is a Divisional of co-pending application Ser. No.12/866,204, filed on Aug. 4, 2010, the entire contents of which arehereby incorporated by reference and for which priority is claimed under35 U.S.C. § 120.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a reissue of U.S. application Ser. No.13/080,339 filed on Apr. 5, 2011, now U.S. Pat. No. 8,205,473 B2 issuedon Jun. 26, 2012, which is a Divisional Application of U.S. applicationSer. No. 12/866,204 filed on Aug. 4, 2010, now U.S. Pat. No. 8,210,009B2 issued on Jul. 3, 2012, which is a National Phase of PCT PatentApplication No. PCT/SE2010/050189 filed on Feb. 18, 2010, which claimspriority to an earlier filed PCT Patent Application No.PCT/SE2010/050006 filed on Jan. 4, 2010 and to Swedish PatentApplication No. 0900207-2 filed on Feb. 18, 2009.

FIELD AND BACKGROUND OF THE INVENTION

The present invention relates to a key for use in a cylinder lock with arotatable key plug having a profiled key hole or keyway, said keycomprising:

-   -   an elongated key blade with a relatively wide lower portion and        a relatively narrow upper portion, there being a step-like        transition region between the wider lower portion and the narrow        upper portion,    -   said key blade having a longitudinal profile groove located        adjacent to said step-like transition region and extending along        at least a portion of the length of the key blade, with an inner        wall of said groove being substantially parallel to a side        surface of said lower portion of said key blade,    -   said longitudinal profile groove having an undercut portion        adjacent to and inside a ridge portion of the key blade, the        outside of said ridge portion forming a part of said side        surface of the key blade in said relatively wide lower portion        up to said step-like transition region, and the inside of said        ridge portion facing said inner wall of said groove.

Such a key with an undercut groove is previously known, e.g. from U.S.Pat. No. 5,715,717 (Widén) or U.S. Pat. No. 5,640,865 (Widén). Such keyshave proven to be very useful in that they provide an improved security.The key profile is quite distinguished from conventional keys, and it israther difficult to copy such keys. Moreover, they permit a greatvariation of the cross-sectional profile, which is a great advantage.

OBJECT OF THE INVENTION

However, over time, there is a constant need for further distinguishingprofiles and many more possible variations thereof.

A further object of the invention is to make it even more difficult tocopy such profiled keys with ordinary lock smith tools.

SUMMARY OF THE INVENTION

In order to achieve these objects, the undercut portion of thelongitudinal profile groove, at its innermost part inside said ridgeportion, is extended or expanded downwardly, preferably substantially ina direction in parallel to said side surface of the key blade, into alongitudinal pocket having opposite lateral wall portions and alowermost transverse end wall, which is substantially flat or slightlycurved, and which is substantially parallel to a lower edge portion ofthe key blade and faces upwardly in a direction in a central plane ofthe key blade.

The inside wall of the ridge portion may be substantially parallel to aside surface of the key blade, so that the ridge portion forms a massiveand strong material portion extending in parallel to the side surface ofthe key blade. The pocket inside the ridge portion may have asubstantially rectangular cross-section, a substantially circularcross-section, with a relatively large curvature, or some otherconfiguration.

In this way, the material of the key blade is used in an optimum way,and a new kind of profile is obtained, and it will be very difficult tocopy such keys, especially if they are produced by stamping and milling.A cutting disc is normally not enough. Rather, it may be necessary touse broaching tools and a well-controlled use of such tools in order tosecure exact dimensions of the pocket-like extension of the groove. Thisis of great importance for key control and high security to the end userof the key.

With such a configuration of the undercut groove, many advantages areobtained at the same time, as will be explained further below.

Other preferable features are stated in the dependent claims and willappear from the detailed description below.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described more fully below with reference to theappended drawings.

FIG. 1 and FIG. 2 illustrate a prior art lock and key combination;

FIG. 3 shows a side view of the key illustrated in FIG. 2;

FIG. 4 is a cross-section through the prior art lock with an insertedkey;

FIG. 5 is a cross-sectional view of the prior art key blade;

FIG. 6 shows a side view of a profiled key according to the presentinvention for an embodiment with a wave-like code pattern;

FIG. 7 is a cross-section through the key of FIG. 6;

FIG. 8 is a cross-section through an associated lock with a key plug anda side tumbler;

FIG. 9 is a similar view of a lock and an inventive key inserted intothe lock;

FIGS. 10-17 are cross-sectional views of some additional embodiments ofthe profiled key according to the invention (the upper part of the keybeing taken away), and

FIGS. 18-26 are similar cross-sectional views of some further modifiedembodiments of the profiled key according to the invention.

BRIEF DESCRIPTION OF SOME PREFERRED EMBODIMENTS

FIGS. 1 through 5 show a prior art lock and key system with a key bladehaving an undercut profile groove in a side surface thereof, such as thesystem disclosed in U.S. Pat. No. 5,715,717 (Widén). The lock 10 is ofthe kind having a housing 11 with locking pins 14 in an upper portionthereof and a rotatable key plug 12 accommodated in a cylindrical boreof the housing. In the key plug 12, there is a central longitudinalkeyway or key hole 13 having a sectional profile corresponding to anassociated key 20 provided with conventional recesses 21 at the upperedge thereof and a profile groove 22 at a side surface 23 of the keyblade. As appears from FIG. 3, the key also has a grip portion 24.

The operation of the lock is more readily understood from thecross-sectional view in FIG. 4. The key plug 12 is rotatable within thehousing 11 and can be locked against rotation by means of a longitudinalrow of upper and lower locking pins 14a, 14b. Each pair of such lockingpins can be positioned with their abutting end surfaces at the shearline between the key plug 12 and the housing 11. In this position, asshown in FIG. 4, the key plug 12 is rotatable. Here, as is well-known inthe art, the locking pins are positioned so as to release the lock bymeans of a properly cut key 20.

The full profile of the key 20 (of prior art design) is illustrated inFIG. 5, as disclosed e.g. in the above-mentioned U.S. Pat. No. 5,715,717(Widén). Accordingly, this prior art key has a longitudinal profilegroove 22 extending longitudinally along the key blade at a depth whichis slightly greater than half the thickness of the key blade. In FIG. 5,the central a plane of the key blade is denoted by the letter “A”. Thelongitudinal groove 22 has an inner wall 24 surface 241 and oppositewalls upper wall surface 25 and lower side wall surface 26. An inclinedportion 25a extends upwardly from the upper wall surface 25. One ofthese opposite walls the wall surfaces, in particular the lower sidewall or surface 26 located closest to the base edge 27 of the key blade,is undercut and extends in a plane being inclined so as to face inwardlytowards the inner wall or surface 24 241. This lower side wall surface26 of the undercut groove 22 forms an inside wall surface of a ridgeportion 28, the outside of which forms part of the above mentioned sidesurface 23 of the key blade.

The prior art key blade shown in FIGS. 2,3, 4 and 5 also has two furtherlongitudinal grooves 30 and 31 on the other side of the key (to the leftin FIG. 5).

The undercut portion 29 of the longitudinal groove 22 has manyadvantages, as explained in the above-mentioned U.S. Pat. No. 5,715,717(Widén), especially with regard to increasing the number of possibleprofile variations, improved resistance against picking the lock andhigh security against unauthorized key copying.

According to the present invention and as illustrated in FIG. 6 through9, a further improvement resides in a modification of the undercutgroove. This modification comprises an expansion or extension of theinnermost part of the undercut portion of the groove 122 (FIG. 7) so asto form a longitudinal pocket-like configuration 135.

In FIG. 7, all reference numerals relating to the key correspond tothose shown in FIG. 5, although they have been supplemented with thedigit “1” before the number given in FIG. 5.

Also, in the embodiments shown in FIGS. 6-9, the a one piece key blade120 has a relatively wide lower portion 140 and a relatively narrowupper portion 141, there being a shelf or step surface 142 in thetransition region between the wider lower portion 140 and the narrowupper portion 141. The wider lower portion extends farther in a lateraldirection relative to the narrow upper portion to form a step-liketransition. The longitudinal profile groove 122 is located adjacent tothis shelf surface 142. This structure with a shelf or step surface ispreviously known per se.

TheAs illustrated in FIG. 7, the downwardly extended pocket-likeconfiguration 135 of the modified undercut groove 122, is (in thisparticular embodiment) substantially rectangular in cross-section, withopposite lateral walls 132 and 133 being parallel to each other, and alowermost transverse end wall 134, being parallel to the lower edgesurface 127 of the one piece key blade and facing upwardly in thedirection of the central plane A of the one piece key blade. The onepiece key blade 120 has the step-like transition formed by an externalside wall surface 123 at the lower part of the one piece key blade 120that is in a plane which is parallel to an upper side surface 1123′ ofthe one piece key blade 120 at an upper part thereof, above saidlongitudinal profile groove 122. The lowermost transverse end wall 134of the pocket 135 faces upwardly in a direction opposite to a verticaldirection (VD) towards an upper wall surface 144 that is formed by aprojecting surface 143 on the upper side surface 1123′.

The innermost inner lateral wall surface portion 132 of the pocket-likeextension 135 adjoins with the and merges with the inner wall surface124 of the undercut groove 122, so whereas the opposite outer lateralwall surface portion 133 forms the inside wall surface of the ridgeportion 128, in parallel to the external side wall surface 123 of thekey blade.

Thus, the surfaces 123, 133 and 132 are substantially parallel to eachother. The one piece key blade 120 includes an undercut portion 129 ofthe longitudinal profile groove 122 which, at an innermost part, isextended further substantially in the same direction as the verticaldirection (VD) into a longitudinal, substantially uniformly wide pocket135 having a uniform width with opposite inner and outer substantiallyparallel lateral wall surface portions 132, 133. The undercut portion orlongitudinal profile groove 122 is defined at an upper part thereof by asmallest opening width (w), as seen perpendicularly to the external sidewall surface 123 of the lower portion of said one piece key blade 120between an upper wall 144 and the ridge portion 128. The verticaldimension (h) of the ridge portion 128 is equal to or greater than halfof said smallest opening width (w). The inner wall surface 124 of saidlongitudinal profile groove 122 is located at a distance from theexternal side wall surface 123 of the one piece key blade 120 which isgreater than half the thickness of the one piece key blade 120.

According to a first aspect of the invention, the undercut portion 129of the longitudinal profile groove 122, at an innermost part, isextended further substantially in the same direction as the verticaldirection (VD) into a longitudinal substantially uniformly wide pocket135 having a uniform width with opposite inner and outer substantiallyparallel lateral wall surface portions 132, 133 wherein the inner wallsurface 124 of the longitudinal profile groove 122 adjoins the innerlateral wall surface portion 132 of the pocket 135. The inner lateralwall surface portion 132 of the pocket 135 extends downwardly to alowermost transverse end wall surface 134, which is substantially flator slightly curved, and which is substantially parallel to a lowermostedge wall surface 127 of the one piece key blade 120 and which facesupwardly in a direction opposite to the vertical direction (VD) towardsthe upper wall surface 144 of the longitudinal profile groove 122 withthe opposite lateral wall surface portions 132, 133 of the pocket 135being substantially parallel to the external side wall surface 123 ofthe one piece key blade 120.

According to a second aspect of the invention, the undercut portion 129of the longitudinal profile groove 122, at an innermost part, isexpanded downwardly into a longitudinal widened pocket 1353 having alarger width relative to the longitudinal profile groove 122. Thelongitudinal widened pocket is formed by opposite inner and outerlateral wall surface portions and the inner lateral wall surface portion1323 of the longitudinal profile groove 122 is connected to the innerwall surface of the longitudinal profile groove 122. The lowermosttransverse end wall surface 1343 faces upwardly in a direction oppositeto the vertical direction (VD) towards the upper wall surface 144 of thelongitudinal profile groove 122 and at least a part of one of saidopposite lateral wall surface portions of the longitudinal widenedpocket 1353 is a circular arc. The longitudinal widened pocket 1353extends downwardly in the same direction as the vertical direction (VD)of said undercut portion 129.

According to a third aspect of the invention, the undercut portion 129of the longitudinal profile groove 122, at an innermost part is extendedfurther substantially in the same direction as the vertical direction(VD) into a longitudinal pocket 135 being interrupted by at least onelongitudinal recess formed in at least one of opposite inner and outerlateral wall surface portions 132, 133 wherein the inner wall surface1243 of the longitudinal profile groove 122 adjoins the inner lateralwall surface portion 1324, located opposite to the ridge portion. Theinner lateral wall surface portion 1324 extends downwardly to alowermost transverse end wall surface 134, the lowermost transverse endwall surface 134 being substantially flat or slightly curved, and beingsubstantially parallel to a lowermost edge wall surface 127 of the onepiece key blade 120 and which faces upwardly in a direction opposite tothe vertical direction (VD) towards the upper wall surface 144 of thelongitudinal profile groove 122 with the opposite lateral wall surfaceportions 132, 133 of the pocket 135 being substantially parallel to theexternal side wall surface 123 of the one piece key blade 120.

The ridge portion 128 is somewhat longer, measured in parallel to thecentral plane A of the key blade, than the prior art structure (FIG. 5)and reaches up to the step-like transition region 142. Moreparticularly, the ridge portion 128 has a vertical dimension h, which ismore than half of the smallest opening width w of the undercut groove122, this smallest opening width w being measured as a perpendicularprojection onto the inner wall 124 of the longitudinal groove 122. Also,preferably, the vertical dimension h of the ridge portion 128 is greaterthan the distance d between the lowermost transverse end wall 134 andthe lower edge surface 127 of the key blade. In this embodiment, thevertical dimension h of the ridge portion 128 is equal to or greaterthan the smallest opening width w. This structure is advantageous forseveral reasons:

-   -   by varying the width, depth (in the plane A) and longitudinal        extension of the pocket-like configuration, the profile shape        can be varied considerably;    -   because of the opposite lateral wall portions 132, 133 the total        width of the undercut portion of the profile groove 122 can be        accommodated in a limited region laterally, so that the total        width of the key blade can be kept rather small. It appears from        FIGS. 5 and 7 that the total width of the new key blade is about        the same;    -   the corresponding tongue portion, which may form a part of a        longitudinal rib 150 at a side wall of the key way (see FIGS. 8        and 9), will be stronger and does not have to have a pointed or        sharp end portion, as in the prior art structure (compare FIG.        4);    -   the pocket-like extension 135 of the undercut portion of the        groove 122 will make it much more difficult to make copies of        such keys, since it may not be sufficient to use only a cutter        disk. Normally, other tools also have to be used. Accordingly it        will be difficult for others than specialized manufacturers to        produce such key blanks;    -   the relatively long vertical extension of the ridge portion 128,        in parallel to the central plane A of the key blade, will make        it possible to cut rather deep recesses in the ridge portion.        Accordingly, just like in the prior art embodiment of FIGS. 1-5,        it is possible to provide many vertical levels of code recesses        in this material region, see FIG. 6. Of course, this will also        facilitate lock and key systems having a very high number of        code combinations.

In FIGS. 8 and 9 there is shown an embodiment with a side lockingtumbler 105, which is guided in a cylindrical cavity 106 in therotatable key plug 112. In principle, the arrangement is similar tothose disclosed in the U.S. Pat. Nos. 4,756,177 (Widén) and 5,715,717(Widén).

The parts that correspond to the previous, prior art embodiment (FIG. 5)have been given the same reference numerals, with the digit “1” addedbefore the numbers shown in FIG. 5.

Accordingly, the side tumbler 105 is (in this embodiment) rotatablearound its cylindrical axis, so that a transversally projecting finger105a will pivot back and forth when the projecting finger 105a follows awave-like coded surface on the side of the key blade (see FIG. 6), inthis case in the ridge portion 128 (see FIG. 7). When the side tumbler105 is correctly positioned, a recess 105b in its cylindrical surfacewill register with corresponding projections 108a on a side bar 108(FIG. 9). In this way, the side bar may move radially inwards so as topermit rotation of the key plug 112.

The projecting finger 105a on the side tumbler 105 will contact thewave-like code pattern on the side of the key blade 120, as shown inFIG. 6, while pivoting back and forth and also moving vertically up anddown. When the key blade is fully inserted, the various side tumblerprojections 105a will be located in the concavities 102a, 102b, 102c,102d, 102e and possibly also (or alternatively) onto an upper codesurface portion 102f at an uppermost extra code level. Such an upper,extra code level is disclosed in the published international patentapplication WO2005/028789 (Winloc et al).

It would be possible to provide an even deeper pocket-like extension 135of the undercut portion of the profile groove, in parallel to thecentral vertical plane A of the key blade. Then, the number of possiblecode levels in the ridge portion 133 128 (see FIGS. 6 and FIG. 7) wouldbe larger than in prior art structures.

It should be noted that the new configuration of the undercut groove122, with the pocket-like extension 135, is useful even without having aside tumbler 105. Then, the ridge portion is basically continuous anddoes not have any cuts or codes.

Also, if at least one side tumbler is used, it does not have to berotatable, but can be guided for elevational movement only. Furthermore,the side tumbler does not have to operate as a locking means for lockingthe key plug against rotation. Alternatively, it may serve only as ablocking element, which prevents incorrectly cut keys from being fullyinserted into the key way 13 of the lock 10. Such a blocking element isdisclosed in a patent application being filed by the same applicant onthe same day as the earliest priority date of this application(WO2010/096007 A1).

The exact configuration or shape of the longitudinally extending pocketmay be modified in various ways within the scope of the presentinvention. In FIG. 10, there is shown an embodiment where the inner wall124 surface 124′ of the longitudinal profile groove 122 122′ of the keyblade 120′ merges smoothly with the adjoining inner lateral wall 132surface 132′ of the vertically oriented pocket-like configuration 135,135′ just like in FIG. 7. The external side wall surface 123′ issubstantially parallel to the inner lateral wall surface 132′.

In FIG. 11, the pocket-like configuration 135 135″ is similar to the onein FIG. 7, but it is slightly wider and the lowermost transverse endwall 134′ surface 134″ is rounded or curved. In addition, FIG. 11illustrates the undercut portion 129′ and the undercut groove 122″.Further, the vertical direction (VD) is illustrated in FIG. 11.

The embodiment shown in FIG. 12 includes a lower side wall 126′ and issimilar to the one embodiment in FIG. 10 11, but and the lowermosttransverse end wall surface 134″ is curved. The inner wall 124 surface124″ of the groove merges smoothly with the adjoining inner lateral wall132 surface 132″. In FIGS. 11 and 12, the lowermost transverse end wallsurface 134″ of the pocket 135″ is curved with a radius being more thanhalf of a width of the pocket 135. The width is measured transversely tothe external side wall surface 123 of the one piece key blade 120.

In FIG. 13, the pocket-like configuration 135′ 1353 is modified into acircular cross-section. Accordingly, in this embodiment, the lateralwalls 132, 133 wall surfaces 1323, 133′ and the lowermost end wall 134surface 1343 are all formed as circular arcs merging with each other.

The embodiment shown in FIG. 14 is like the one shown in FIG. 10, butthe inner lateral wall 132 surface 1324 adjoining the inner wall 124surface 1243 is provided with a longitudinal recess 132a, which isrectangular in cross-section.

The embodiment of FIG. 15 is similar to the one of FIG. 14, but there isalso a longitudinal recess 133a in the outer lateral wall 133 133″opposite to the longitudinal recess 132a 132a′ in the lateral wall 1325.

The embodiment in FIG. 16 is similar to the one in FIG. 15, but there isa longitudinal rib 133b (instead of a recess 133a) opposite to thelongitudinal recess 132a 132a″.

The modified embodiment shown in FIG. 17 comprises relatively smalllongitudinal recesses 132c, 133c, 134c with part cylindricalpart-cylindrical cross-sections in the lateral walls 133 wall surfaces1333 and 132 1326 and the lowermost end wall 134 surface 1344,respectively. Except for these part-circular recesses, this embodimentis similar corresponds to the one shown in FIG. 11.

The embodiments of FIGS. 14 through 17 are included to illustrate thatthe opposite lateral wall surface portions and the lowermost transverseend wall surface of the longitudinal pocket may be provided withirregular surface portions.

Finally, FIGS. 18 through 26 show modified embodiments similar to thoseshown in FIGS. 10 through 17. Thus, the keys 321 through 328 329 eachhave a cross-sectional profile corresponding to those shown in FIGS. 10through 17, respectively, except that the upper part of the ridgeportion 228 is portions 228′, 228″, 2283, 2284, 2285, 2286, 2287, 2288and 2289 are uniformly thick, and the inside 226 226′, 226″, 2263, 2264,2265, 2266, 2267, 2268 and 2269 thereof is are parallel to the centralplane of the key blade.

FIG. 26 corresponds to FIGS. 11 and 19, except that the lowermosttransverse end wall 234 of the key 329 is flat.

In all embodiments described above, and in the appended claims, it isassumed that the inner wall 124 of the longitudinal undercut groove 122,122′, 122″ is substantially parallel to the central plane A of the keyblade and a side surface the external side wall surfaces 123, 123′, 123″thereof. Within this definition, the inner wall may be oriented at asmall angle to said central plane A, this angle being normally no morethan 15°, in some cases (such as a relatively thick key blade) somewhatlarger.

The longitudinally extending pocket may be shorter than the length ofkey blade and extend along only a portion thereof.

Also, the longitudinal profile rib at the key plug may be interrupted orformed as one or more separate elements mounted in the key plug.

The invention claimed is:
 1. A key for use in a cylinder lock with arotatable key plug having a profiled key way, said key comprising: anelongated one piece key blade (120) with a relatively wide lower portionand a relatively narrow upper portion, there being a step-liketransition region between the wider lower portion and the narrow upperportion, said one piece key blade (120) having a longitudinal profilegroove (122) located adjacent to said step-like transition region andextending along at least a portion of the length of the one piece keyblade, with an inner wall (124) surface of said groove being orientedsubstantially in parallel to or at a small angle, no more than 15°, to aan external side wall surface (123) of said lower portion of said onepiece key blade, said longitudinal profile groove (122) having, at alower part thereof, an undercut portion (129) adjacent to and inside aridge portion (128) of the one piece key blade, the outside of saidridge portion forming a part of said external side wall surface (123) ofsaid lower portion of the one piece key blade, in said relatively widelower portion up to said step-like transition region (142), and theinside of said ridge portion facing being opposite said inner wallsurface of said longitudinal profile groove, said longitudinal profilegroove (122) defining, at an upper part thereof, a smallest openingwidth (w), as seen perpendicularly to said external side wall surface(123) of said lower portion of said one piece key blade, between anupper wall (144) surface and said ridge portion (128), wherein: saidundercut portion of said longitudinal profile groove extends downwardlysubstantially in a vertical direction (VD) in parallel to said externalside wall surface of said one piece key blade, said undercut portion(129) of said longitudinal profile groove (122), at its an innermostpart inside said ridge portion (128), is extended or expandeddownwardly, further substantially in a the same direction as saidvertical direction which is substantially parallel to said side surface(123) of the key blade, (VD) into a longitudinal substantially uniformlywide pocket (135) having a uniform width with opposite inner and outersubstantially parallel lateral wall surface portions (132, 133) andwherein said inner wall surface of said longitudinal profile grooveadjoins the inner lateral wall surface portion of said pocket, and saidinner lateral wall surface portion of said pocket extends downwardly toa lowermost transverse end wall (134) surface, which is substantiallyflat or slightly curved, and which is substantially parallel to a loweredge portion (127) of the lowermost edge wall surface of the one piecekey blade and which faces upwardly in a direction being parallel tocentral plane (A) of the key blade opposite to said vertical direction(VD) towards said upper wall (144) surface of said longitudinal profilegroove (122) with said opposite lateral wall surface portions (132, 133)of said pocket (135) being substantially parallel to said external sidewall surface (123) of the flat one piece key blade (120).
 2. The key asdefined in claim 1, wherein the a vertical dimension (h) of said ridgeportion (128) is greater than the distance (d) between said lowermosttransverse end wall (134) of said groove surface and said lowerlowermost edge wall surface (127) of the one piece key blade.
 3. The keyas defined in claim 1, wherein said pocket (135) has a substantiallyrectangular cross-section.
 4. The key as defined in claim 1, whereinsaid inner wall (124) of said longitudinal profile groove (122) mergeswith one of said opposite lateral walls portions (132, 133) of saidpocket.
 5. The key as defined in claim 1, wherein the a verticaldimension (h) of said ridge portion (128), measured in a plane of saidlower side wall surface (123) of the one piece key blade (120), is morethan half of the said smallest opening width (w) of said longitudinalprofile groove (122) adjacent to said external side wall surface (123),said smallest opening width (w) being measured as a perpendicularprojection onto said innerwall (124) inner wall surface of saidlongitudinal profile groove (122).
 6. The key as defined in claim 5,wherein said vertical dimension (h) of said ridge portion (128) is equalto or greater than said smallest opening width (w).
 7. The key asdefined in claim 1, constituting wherein the one piece key blade isformed from a key blank with a continuous upper edge portion configuredso as to permit coded recesses to be cut therein.
 8. The key as definedin claim 1, having coded recesses (102a . . . 102e) cut into said ridgeportion (128), so as to form a side code on the one piece key blade,said side code recesses being configured to cooperate with at least oneside tumbler (105) in an associated lock.
 9. The key as defined in claim8, wherein said side code recesses (102a . . . 102e) forming a side codeconstitute a wave-like, longitudinal code pattern.
 10. The key asdefined in claim 8, wherein said side code recesses (102a . . . 102e)are cut into the whole material thickness of said ridge portion (128),so that the side code recesses reach all the way from the outsideexternal side wall surface (123) of said ridge portion (128) into saidlongitudinal pocket (135) of the undercut profile groove (122), and theouter lateral wall surface portion of said pocket is interrupted by saidside code recesses.
 11. The key as defined in claim 8, wherein said sidecode recesses (102a . . 102e) are cut from an upper edge of the ridgeportion (128) down to various levels between said upper edge and the alowermost part of said longitudinally extending pocket (135).
 12. Thekey as defined in claim 8, wherein said side code recesses (102a . . .102e) form concavities with lower bottom portions located at a number ofdifferent levels, each representing a code.
 13. The key as defined inclaim 12 11, wherein said different various levels also include anuppermost level at the upper edge (102f) of said ridge portion (128).14. The key as defined in claim 12 11, wherein the number of differentvarious levels is at least three.
 15. The key as defined in claim 1,wherein the inner wall (124) surface of said longitudinal profile grooveand the adjoining longitudinal pocket (135) are is located at a depthdistance from said external side wall surface (123) of the one piece keyblade (120) which is greater than half the a thickness of said one piecekey blade.
 16. A key for use in a cylinder lock with a rotatable keyplug having a profiled key way, said key comprising: an elongated keyblade (120) with a relatively wide lower portion and a relatively narrowupper portion, there being a step-like transition region between thewider lower portion and the narrow upper portion, said key blade (120)having a longitudinal profile groove (122) located adjacent to saidstep-like transition region and extending along at least a portion ofthe length of the key blade, with an inner wall (124) of said groovebeing oriented substantially in parallel to or at a small angle, no morethan 15°, to a side surface (123) of said lower portion of said keyblade, said longitudinal profile groove (122) having, at a lower partthereof, an undercut portion (129) adjacent to and inside a ridgeportion (128) of the key blade, the outside of said ridge portionforming a part of said side surface (123) of said lower portion of thekey blade, in said relatively wide lower portion up to said step-liketransition region (142), and the inside of said ridge portion facingsaid inner wall of said groove, said longitudinal profile groove (122)defining, at an upper part thereof, a width (w), perpendicularly to saidside surface (123) of said lower portion of said key blade, between anupper wall (144) and said ridge portion (128), wherein said undercutportion (129) of said longitudinal profile groove (122), at itsinnermost part inside said ridge portion (128), is extended or expandeddownwardly, in a direction which is substantially parallel to said sidesurface (123) of the key blade, into a longitudinal substantiallybulbous pocket (135) having a larger width relative to the longitudinalprofile groove (122), said bulbous pocket (135) being formed by oppositelateral wall portions (132, 133) and a lowermost transverse end wall(134) which is slightly curved and faces upwardly in a direction of acentral plane (A) of the key blade towards said upper wall (144) of saidlongitudinal profile groove (122).
 17. The key as defined in claim 16,wherein the vertical dimension (h) of said ridge portion (128) isgreater than the distance (d) between said lowermost transverse end wall(134) of said groove and said lower edge surface (127) of the key blade.18. The key as defined in claim 16, wherein at least one of saidopposite lateral wall portions (132, 133) is curved.
 19. The key asdefined in claim 16, wherein said lowermost transverse end wall (134′,134″) of said pocket (135) is curved with a radius being more than halfof the width of said pocket, said width being measured transversely tosaid side surface (123) of said key blade (120).
 20. The key as definedin claim 16, wherein said inner wall (124) of said longitudinal profilegroove (122) merges with one of said opposite lateral walls portions(132, 133) of said pocket.
 21. The key as defined in claim 16, whereinthe vertical dimension (h) of said ridge portion (128), measured in aplane of said side surface (123) of the key blade (120), is more thanhalf of the smallest width (w) of said longitudinal profile groove (122)adjacent to said side surface (123), said smallest width (w) beingmeasured as a perpendicular projection onto said inner wall (124) ofsaid longitudinal profile groove (122).
 22. The key as defined in claim21, wherein said vertical dimension (h) of said ridge portion (128) isequal to or greater than said smallest width (w).
 23. The key as definedin claim 16, constituting a key blank with a continuous upper edgeportion configured so as to permit coded recesses to be cut therein. 24.The key as defined in claim 16, having coded recesses (102a . . . 102e)cut into said ridge portion (128), so as to form a side code on the keyblade, said side code recesses being configured to cooperate with atleast one side tumbler (105) in an associated lock.
 25. The key asdefined in claim 24, wherein said side code recesses (102a . . . 102e)forming a side code constitute a wave-like, longitudinal code pattern.26. The key as defined in claim 24, wherein said side code recesses(102a . . . 102e) are cut into the whole material thickness of saidridge portion (128), so that the side code recesses reach all the wayfrom the outside surface (123) of said ridge portion (128) into saidlongitudinal pocket (135) of the undercut profile groove (122).
 27. Thekey as defined in claim 24, wherein said side code recesses (102a . . .102e) are cut from an upper edge of the ridge portion (128) down tovarious levels between said upper edge and the lowermost part of saidlongitudinally extending pocket (135).
 28. The key as defined in claim24, wherein said side code recesses (102a . . . 102e) form concavitieswith lower bottom portions located at a number of different levels, eachrepresenting a code.
 29. The key as defined in claim 28, wherein saiddifferent levels also include an uppermost level at the upper edge (1020of said ridge portion (128).
 30. The key as defined in claim 28, whereinthe number of different levels is at least three.
 31. The key as definedin claim 16, wherein the inner wall (124) of said longitudinal profilegroove and the adjoining longitudinal pocket (135) are located at adepth from said side surface (123) of the key blade (120) which isgreater than half the thickness of said key blade.
 32. A key for use ina cylinder lock with a rotatable key plug having a profiled key way,said key comprising: an elongated one piece key blade (120) with arelatively wide lower portion and a relatively narrow upper portion,there being a step-like transition region between the wider lowerportion and the narrow upper portion, said one piece key blade (120)having a longitudinal profile groove (122) located adjacent to saidstep-like transition region and extending along at least a portion ofthe length of the one piece key blade, with an inner wall (124) surfaceof said groove being oriented substantially in parallel to or at a smallangle, no more than 15°, to a side substantially parallel to an externalside wall surface (123) of said lower portion of said one piece keyblade, said longitudinal profile groove (122) having, at a lower partthereof, an undercut portion (129) adjacent to and inside a ridgeportion (128) of the one piece key blade, the outside of said ridgeportion forming a part of said external side wall surface (123) of saidlower portion of the one piece key blade, in said relatively wide lowerportion up to said step-like transition region (142), and the inside ofand said ridge portion facing being opposite to said inner wall surfaceof said longitudinal profile groove, said longitudinal profile groove(122) defining, at an upper part thereof, a smallest opening width (w),as seen perpendicularly to said external side wall surface (123) of saidlower portion of said one piece key blade, between an upper wall (144)surface and said ridge portion (128), wherein: said undercut portion ofsaid longitudinal profile groove extends downwardly substantially in avertical direction (VD) in parallel to said external side wall surfaceof said one piece key blade, said undercut portion (129) of saidlongitudinal profile groove (122), at its an innermost part inside saidridge portion (128), is extended or expanded downwardly, is extendedfurther substantially in a the same direction as said vertical directionwhich is substantially parallel to said side surface (123) of the keyblade, (VD) into a longitudinal pocket (135) having being interrupted atleast one longitudinal recess formed in at least one of the oppositeinner and outer lateral wall surface portions (132, 133) and whereinsaid inner wall surface of said longitudinal profile groove adjoins saidinner lateral wall surface portion, located opposite to said ridgeportion, and said inner lateral wall surface portion extends downwardlyto a lowermost transverse end wall (134) surface, said lowermosttransverse end wall (134) surface being substantially flat or slightlycurved, and being substantially parallel to a lower edge portion (127)of the lowermost edge wall surface of the one piece key blade and whichfaces upwardly in a direction being parallel to central plane (A) of thekey blade opposite to said vertical direction (VD) towards said upperwall (144) surface of said longitudinal profile groove (122) with saidopposite lateral wall surface portions (132, 133) of said pocket (135)being substantially parallel to said external side wall surface (123) ofthe flat one piece key blade (120).
 33. The key as defined in claim 32,wherein the a vertical dimension (h) of said ridge portion (128) isgreater than the distance (d) between said lowermost transverse end wall(134) surface of said groove and said lower lowermost edge wall surface(127) of the one piece key blade.
 34. The key as defined in claim 32,wherein at least one of said opposite lateral wall portions (132, 133)is curved.
 35. The key as defined in claim 32, wherein said lowermosttransverse end wall (134′, 134″) of said pocket (135) is curved with aradius being more than half of the width of said pocket, said widthbeing measured transversely to said side surface (123) of said key blade(120).
 36. The key as defined in claim 32, wherein said at least one ofsaid longitudinal recess formed in at least one of the opposite lateralwall surface portions (132) and said lowermost transverse end wall (134)surface is provided with an irregular surface portion (132c, 134c). 37.The key as defined in claim 32, wherein said inner wall (124) of saidlongitudinal profile groove (122) merges with one of said oppositelateral walls portions (132, 133) of said pocket.
 38. The key as definedin claim 32, wherein the a vertical dimension (h) of said ridge portion(128), measured in a said plane of said external side wall surface (123)of the one piece key blade (120), is more than half of the smallest saidsmallest opening width (w) of said longitudinal profile groove (122)adjacent to said lower side wall surface (123), said smallest openingwidth (w) being measured as a perpendicular projection onto said innerwall (124) surface of said longitudinal profile groove (122).
 39. Thekey as defined in claim 38, wherein said vertical dimension (h) of saidridge portion (128) is equal to or greater than said smallest openingwidth (w).
 40. The key as defined in claim 32, constituting wherein theone piece key blade is formed from a key blank with a continuous upperedge portion configured so as to permit coded recesses to be cuttherein.
 41. The key as defined in claim 32, having coded recesses (102a. . . 102e) cut into said ridge portion (128), so as to form a side codeon the one piece key blade, said side code recesses being configured tocooperate with at least one side tumbler (105) in an associated lock.42. The key as defined in claim 41, wherein said side code recesses(102a . . 102e) forming a side code constitute a wave-like, longitudinalcode pattern.
 43. The key as defined in claim 41, wherein said side coderecesses (102a . . . 102e) are cut into the whole material thickness ofsaid ridge portion (128), so that the side code recesses reach all theway from the outside external side wall surface (123) of said ridgeportion (128) into said longitudinal pocket (135) of the undercutprofile groove (122).
 44. The key as defined in claim 41, wherein saidside code recesses (102a . . . 102e) are cut from an upper edge of theridge portion (128) down to various levels between said upper edge andthe lowermost part of said longitudinally extending pocket (135). 45.The key as defined in claim 41, wherein said side code recesses (102a .. . 102e) form concavities with lower bottom portions located at anumber of different levels, each representing a code.
 46. The key asdefined in claim 45 44, wherein said different various levels alsoinclude an uppermost level at the upper edge (102f) of said ridgeportion (128).
 47. The key as defined in claim 45 44, wherein the numberof different various levels is at least three.
 48. The key as defined inclaim 32, wherein the inner wall (124) surface of said longitudinalprofile groove and the adjoining longitudinal pocket (135) are islocated at a depth from said side distance from said external side wallsurface (123) of the one piece key blade (120) which is greater thanhalf the a thickness of said one piece key blade.